The present invention relates generally to dental amalgam producing machines and more particularly to such a machine in which the amalgam ingredients are placed in a mulling cup and the cup spun or otherwise agitated to mix the amalgam ingredients.
There are generally two types of amalgam producing machines. In one type, premeasured amounts of the amalgam ingredients are placed in capsules. The dentist, then, merely locks the capsule in place on the machine which then subjects the capsule to very rapid reciprocating motion. A typical machine of this type is illustrated in U.S. Pat. No. 3,602,443.
In another type of machine, the amalgam ingredients are placed in an open cup which is located at one end of a rotating armature. A gear train in the machine then spins the cup while rotating the armature so that the cup spins on its own axis while orbiting the axis of rotation of the armature. Such a machine is illustrated for example in U.S. Pat. No. 3,170,648. The present invention pertains to an improvement in the operation and construction of this latter type of amalgam producing machine.
Because the cup is spun on its axis while orbiting about another point, the apparatus of the prior art usually employed some sort of gear train to develop the desired motion. Also, the spinning cup was restrained on the end of the rotating arm against centrifugal force. This was usually accomplished by a clamp or other mechanical lock. Another method was to provide the cup with an axle which in turn was inserted into a suitable receiver on the end of the rotating arm. A further requirement in this type of apparatus was that the cup have a cover or lid to prevent the amalgam ingredients from riding up and over the walls of the container under the influence of centrifugal force.
Various problems of the prior art, such as care and maintenance of the gear train, special locking or container receiving fixtures and specially configured containers are all eliminated in the present invention. In this respect, the present invention provides a device wherein a loose belt and centrifugal force act to both hold the container on one end of a rotating arm while spinning the container about its own axis. When the arm is not rotating, the container is unrestrained and free to be removed for convenient filling or emptying. Also, the arm is tipped slightly with respect to horizontal so that the axis of the container is tipped from the vertical. With this arrangement, the container can be open and need not have any cover or lid to prevent the spilling over of the ingredients under the influence of centrifugal force.